Recently, portable devices including smartphones, personal digital assistants (PDAs), tablet computers and the like have become widespread. Such portable devices are increasing in display performance and can display color images.
A field-sequential color (FSC) system is one of techniques for displaying color images. In the FSC system, a red (R) light-emitting device, a green (G) light-emitting device and a blue (B) light-emitting device are conventionally used as a light device. In the FSC system, a frame period is separated into three periods (also called three fields), i.e., a light-emitting period of the red (R) light-emitting device, a light-emitting period of the green (G) light-emitting device and a light-emitting period of the blue (B) light-emitting device. Pixels selected for red display (selected R pixels), pixels selected for blue display (selected B pixels) and pixels selected for green display (selected G pixels) are driven in three (R, G, B) fields, respectively. As a light-emitting device, a point source can also be used. More specifically, a light-emitting diode (LED) can be used as the point source.
The selected R, B and G pixels are pixels corresponding to R, G and B signals and selected from pixels two-dimensionally arrayed on a liquid crystal display panel. A display image of the selected R pixels, a display image of the selected B pixels and a display image of the selected G pixels are separately displayed on the liquid crystal display in sequence, but the user can see a color image by persistence of vision. The FSC system is excellent in utilization of light because no color filter is necessary for the liquid crystal display panel.